Catalytic enantioselective reactions .9. 1,2-O-isopropylidene-5-deoxy-5-N,N-dialkyl (or -N-monoalkyl)amino-alpha-D-xylofuranose derivatives as highly-effective chiral catalysts for enantioselective addition of diethylzinc to aliphatic and aromatic aldehydes

A series of new 1,2-O-isopropylidene-5-deoxy-5-N,N-dialkyl (or -N-monoalkyl)amino-alpha-D-xylofuranose derivatives have been prepared from alpha-D-xylose and their enantioselectivities as chiral catalysts for the addition of diethylzinc to aldehydes have been examined. Of the chiral catalysts examined, 5-deoxy-1,2-O-isopropylidene-5-morpholino-alpha-D-xylofuranose provides high enantioselectivity for aromatic and relatively hindered aliphatic aldehydes, and 5-deoxy-5-hexahydroazepinyl-1,2-O-isopropylidene-alpha-D- xylofuranose is highly effective for unhindered aliphatic aldehydes.